1. Field of the Invention
The present invention relates to a developing member to be incorporated into an electrophotographic apparatus, and a process cartridge and an electrophotographic apparatus each using the developing member.
2. Description of the Related Art
A developing member to be used in an electrophotographic apparatus may be used in various temperature environments. Accordingly, a developing member having low temperature dependence has been required. A temperature variation may cause, for example, a change in shape of a developing member due to its thermal expansion. A silicone rubber is suitably used in an elastic layer of a developing member. However, the silicone rubber is more liable to expand thermally than any other rubber is.
It can be said that a variation in size of the elastic layer of a developing member due to its surrounding temperature or humidity is a problem to be solved in order that electrophotographic images having stable quality may be provided. To solve such problem, Patent Literature 1 proposes a silicone rubber composition that provides a silicone rubber having a low expansion coefficient through the addition of an abundance of a silica-based filler having a small surface area. In addition, Patent Literature 2 proposes a silicone rubber composition that provides a silicone rubber having a low viscosity and a low expansion coefficient through the addition of a large amount of silica whose isolated silanol group content has been specified.